Due to the constraints imposed by physical effects and performance degra certain limitations in sustaining the advancement of Moore’s law.Two-dimensional(2D)materials have emerged as highly promising candidates for t...Due to the constraints imposed by physical effects and performance degra certain limitations in sustaining the advancement of Moore’s law.Two-dimensional(2D)materials have emerged as highly promising candidates for the post-Moore era,offering significant potential in domains such as integrated circuits and next-generation computing.Here,in this review,the progress of 2D semiconductors in process engineering and various electronic applications are summarized.A careful introduction of material synthesis,transistor engineering focused on device configuration,dielectric engineering,contact engineering,and material integration are given first.Then 2D transistors for certain electronic applications including digital and analog circuits,heterogeneous integration chips,and sensing circuits are discussed.Moreover,several promising applications(artificial intelligence chips and quantum chips)based on specific mechanism devices are introduced.Finally,the challenges for 2D materials encountered in achieving circuit-level or system-level applications are analyzed,and potential development pathways or roadmaps are further speculated and outlooked.展开更多
Carbonate cements are the most abundant authigenic mineral and impact on physical properties greatly in sandstone reservoir.In this paper,Pinghu Formation of Xihu Sag was taken as a target.Characteristics,distribution...Carbonate cements are the most abundant authigenic mineral and impact on physical properties greatly in sandstone reservoir.In this paper,Pinghu Formation of Xihu Sag was taken as a target.Characteristics,distribution and formation of carbonate cements were investigated via optical microscopy,cathodoluminescence(CL),electron probe and in-situ carbon-oxygen isotope.The results showed that carbonate cements varied in types and shapes.Calcite/dolomite mainly present as poikilotopic cements,while ferrocalcite/ferrodolomite/ankerite generally present as pore-filling cements.Carbon isotope(δ^(13)C)values of carbonate cements were ranging from–7.77‰to–2.67‰,with an average of–4.52‰,while oxygen isotope(δ^(18)O)values were ranging from–18.94‰to–12.04‰,with an average of–14.86‰.Theδ^(13)C/δ^(18)O indicated that the paleo-fluid of carbonate cement was mainly freshwater.Organic carbon mainly came from organic matter within mature source rocks,and inorganic carbon came from dissolution of carbonate debris and early carbonate cements.Distinctiveδ^(13)C/δ^(18)O values manifest that carbonate cements with different types formed in different periods,which make different contributions to the reservoir properties.Calcite/dolomite formed during eodiagenesis(70–90℃)and early mesodiagenesis stage(90–120℃),and were favorable to reservoir owing to their compacted resistance and selective dissolution.Ferrocalcite/ferrodolomite/ankerite formed during middle-late mesodiagenetic stage(above 120℃),and were unfavorable to reservoir due to cementing the residual intergranular pores.Hence,in order to evaluate the reservoir characteristics,it is of significantly important to distinguish different types of carbonate cements and explore their origins.展开更多
Background Serotonin is an important signaling molecule that regulates secretory and sensory functions in the gut.Gut microbiota has been demonstrated to affect serotonin synthesis in rodent models.However,how gut mic...Background Serotonin is an important signaling molecule that regulates secretory and sensory functions in the gut.Gut microbiota has been demonstrated to affect serotonin synthesis in rodent models.However,how gut microbes regulate intestinal serotonin production in piglets remains vague.To investigate the relationship between microbiota and serotonin specifically in the colon,microbial composition and serotonin concentration were analyzed in ileum-cannulated piglets subjected to antibiotic infusion from the ileum when comparing with saline infusion.Microbes that correlated positively with serotonin production were isolated from piglet colon and were further used to investi-gate the regulation mechanisms on serotonin production in IPEC-J2 and a putative enterochromaffin cell line RIN-14B cells.Results Antibiotic infusion increased quantities of Lactobacillus amylovorus(LA)that positively correlated with increased serotonin concentrations in the colon,while no effects observed for Limosilactobacillus reuteri(LR).To understand how microbes regulate serotonin,representative strains of LA,LR,and Streptococcus alactolyticus(SA,enriched in feces from prior observation)were selected for cell culture studies.Compared to the control group,LA,LR and SA supernatants significantly up-regulated tryptophan hydroxylase 1(TPH1)expression and promoted serotonin production in IPEC-J2 cells,while in RIN-14B cells only LA exerted similar action.To investigate potential mechanisms mediated by microbe-derived molecules,microbial metabolites including lactate,acetate,glutamine,andγ-aminobutyric acid were selected for cell treatment based on computational and metabolite profiling in bacte-rial supernatant.Among these metabolites,acetate upregulated the expression of free fatty acid receptor 3 and TPH1 while downregulated indoleamine 2,3-dioxygenase 1.Similar effects were also recapitulated when treating the cells with AR420626,an agonist targeting free fatty acid receptor 3.Conclusions Overall,these results suggest that Lactobacillus amylovorus showed a positive correlation with sero-tonin production in the pig gut and exhibited a remarkable ability to regulate serotonin production in cell cultures.These findings provide evidence that microbial metabolites mediate the dialogue between microbes and host,which reveals a potential approach using microbial manipulation to regulate intestinal serotonin biosynthesis.展开更多
Myc belongs to a family of proto-oncogenes that encode transcription factors.The overexpression of c-Myc causes many types of cancers.Recently,we established a system for screening c-Myc inhibitors and identified anti...Myc belongs to a family of proto-oncogenes that encode transcription factors.The overexpression of c-Myc causes many types of cancers.Recently,we established a system for screening c-Myc inhibitors and identified antimycin A by screening the RIKEN NPDepo chemical library.The specific mechanism of promoting tumor cell metastasis by high c-Myc expression remains to be explained.In this study,we screened approximately 5,600 microbial extracts using this system and identified a broth prepared from Streptomyces sp.RK19-A0402 strongly inhibits c-Myc transcriptional activity.After purification of the hit broth,we identified compounds closely related to the aglycone of cytovaricin and had a structure similar to that of oligomycin A.Similar to oligomycin A,the hit compounds inhibited mitochondrial complex V.The mitochondria dysfunction caused by the compounds induced the production of reactive oxygen species(ROS),and the ROS activated GSK3α/βthat phosphorylated c-Myc for ubiquitination.This study provides a successful screening strategy for identifying natural products as potential c-Myc inhibitors as potential anticancer agents.展开更多
Combining 3D printing with precursor-derived ceramic for fabricating electromagnetic(EM) wave-absorbing metamaterials has attracted great attention. This study presents a novel ultraviolet-curable polysiloxane precurs...Combining 3D printing with precursor-derived ceramic for fabricating electromagnetic(EM) wave-absorbing metamaterials has attracted great attention. This study presents a novel ultraviolet-curable polysiloxane precursor for digital light processing(DLP) 3D printing to fabricate ceramic parts with complex geometry, no cracks and linear shrinkage. Guiding with the principles of impedance matching, attenuation, and effective-medium theory, we design a crosshelix-array metamaterial model based on the complex permittivity constant of precursor-derived ceramics. The corresponding ceramic metamaterials can be successfully prepared by DLP printing and subsequent pyrolysis process, achieving a low reflection coefficient and a wide effective absorption bandwidth in the X-band even under high temperature. This is a general method that can be extended to other bands, which can be realized by merely adjusting the unit structure of meta-materials. This strategy provides a novel and effective avenue to achieve “target-design-fabricating” ceramic metamaterials, and it exposes the downstream applications of highly efficient and broad EM wave-absorbing materials and structures with great potential applications.展开更多
The repair of osteochondral defects is one of the major clinical challenges in orthopaedics.Well-established osteochondral tissue engineering methods have shown promising results for the early treatment of small defec...The repair of osteochondral defects is one of the major clinical challenges in orthopaedics.Well-established osteochondral tissue engineering methods have shown promising results for the early treatment of small defects.However,less success has been achieved for the regeneration of large defects,which is mainly due to the mechanical environment of the joint and the heterogeneous nature of the tissue.In this study,we developed a multi-layered osteochondral scaffold to match the heterogeneous nature of osteochondral tissue by harnessing additive manufacturing technologies and combining the established art laser sintering and material extrusion techniques.The developed scaffold is based on a titanium and polylactic acid matrix-reinforced collagen“sandwich”composite system.The microstructure and mechanical properties of the scaffold were examined,and its safety and efficacy in the repair of large osteochondral defects were tested in an ovine condyle model.The 12-week in vivo evaluation period revealed extensive and significantly higher bone in-growth in the multi-layered scaffold compared with the collagen–HAp scaffold,and the achieved stable mechanical fixation provided strong support to the healing of the overlying cartilage,as demonstrated by hyaline-like cartilage formation.The histological examination showed that the regenerated cartilage in the multi-layer scaffold group was superior to that formed in the control group.Chondrogenic genes such as aggrecan and collagen-II were upregulated in the scaffold and were higher than those in the control group.The findings showed the safety and efficacy of the cell-free“translation-ready”osteochondral scaffold,which has the potential to be used in a one-step surgical procedure for the treatment of large osteochondral defects.展开更多
Plant glandular trichomes(GTs)are epidermal outgrowths with the capacity to biosynthesize and secrete specialized metabolites,that are of great scientific and practical significance.Our understanding of the developmen...Plant glandular trichomes(GTs)are epidermal outgrowths with the capacity to biosynthesize and secrete specialized metabolites,that are of great scientific and practical significance.Our understanding of the developmental process of GTs is limited,and no single plant species serves as a unique model.Here,we review the genetic mechanisms of GT initiation and development and provide a summary of the biosynthetic pathways of GT-specialized metabolites in nonmodel plant species,especially horticultural crops.We discuss the morphology and classification of GT types.Moreover,we highlight technological advancements in methods employed for investigating GTs.Understanding the molecular basis of GT development and specialized metabolites not only offers useful avenues for research in plant breeding that will lead to the improved production of desirable metabolites,but also provides insights for plant epidermal development research.展开更多
Two-dimensional(2D)tungsten selenide(WSe_(2))is promising candidate material for future electronic applications,owing to its potential for ultimate device scaling.For improving the electronic performance of WSe_(2)-ba...Two-dimensional(2D)tungsten selenide(WSe_(2))is promising candidate material for future electronic applications,owing to its potential for ultimate device scaling.For improving the electronic performance of WSe_(2)-based field-effect transistors(FETs),the modification of surface properties is essential.In this study,the seamless structural phase transition in WSe_(2) lattice is achieved by soft oxygen plasma,regulating the electrical conductance of WSe_(2)-based FETs.We found that during the soft oxygen plasma treatment with optimal processing time,the generated oxygen ions can substitute some selenium atoms and thus locally modify the bond length,inducing 2H→1T phase transition in WSe_(2) with seamless interfaces.The mosaic structures have been proven to tailor the electronic structure and increase the hole carrier concentration inside WSe_(2),significantly increasing the channel conductance of WSe_(2) FETs.With the further increase of the oxygen plasma treatment time,the creation of more selenium vacancy defects leads to the electronic doping,resulting in the reduction of conductance.Benefiting from the hexagonal boron nitride(h-BN)encapsulation to interrupt the partial structural relaxation from 1T to 2H phase,our WSe_(2) FET exhibits high electronic stability with conductance of 6.8×10^(-4) S,which is about four orders of magnitude higher than 2H WSe_(2)(5.8×10^(-8) S).This study could further broaden the WSe_(2) FETs in applications for functionalization and integration in electronics.展开更多
Hepatocellular carcinoma(HCC)is one of the most common malignancies and a leading cause of cancer-related death worldwide.Surgery remains the primary and most successful therapy option for the treatment of early-and m...Hepatocellular carcinoma(HCC)is one of the most common malignancies and a leading cause of cancer-related death worldwide.Surgery remains the primary and most successful therapy option for the treatment of early-and mid-stage HCCs,but the high heterogeneity of HCC renders prognostic prediction challenging.The construction of relevant prognostic models helps to stratify the prognosis of surgically treated patients and guide personalized clinical decision-making,thereby improving patient survival rates.Currently,the prognostic assessment of HCC is based on several commonly used staging systems,such as Tumor-Node-Metastasis(TNM),Cancer of the Liver Italian Program(CLIP),and Barcelona Clinic Liver Cancer(BCLC).Given the insufficiency of these staging systems and the aim to improve the accuracy of prognostic prediction,researchers have incorporated further prognostic factors,such as microvascular infiltration,and proposed some new prognostic models for HCC.To provide insights into the prospects of clinical oncology research,this review describes the commonly used HCC staging systems and new models proposed in recent years.展开更多
Wire electrochemical machining(WECM) is a flexible and effective method for machining complex-shaped metal components, but the ability to machine large-thickness workpieces is hampered by the difficulty of transportin...Wire electrochemical machining(WECM) is a flexible and effective method for machining complex-shaped metal components, but the ability to machine large-thickness workpieces is hampered by the difficulty of transporting electrolytic products in the narrow machining gap. This paper proposes a novel hybrid machining technique that combines the characteristics of WECM and wire electric discharge machining(WEDM), namely, helical wire electrochemical discharge machining. The formation mechanism of electrical discharge in salt-glycol solution was elucidated.Experiments and simulation were conducted to verify the machining mechanism and investigate the performance of the proposed technique. The results show that as the recast layer can be removed by electrochemical action during the proposed process, the surface quality is effectively improved.Minimum surface roughness of the slit sidewall after machining reaches Ra= 0.12 μm. Minimum standard deviation of the slit after machining reaches 5 μm. Moreover, the existence of the discharges significantly improves the transport of the electrolytic products, thus ensuring high machining efficiency. In the experiments, the maximum feed rate of the helical wire electrochemical discharge machining reaches 7 μm/s(12.6 mm^(2)/min). Finally, mortise structures of Inconel 718 with good machining accuracy and surface quality are fabricated with a feed rate of 5 μm/s(9 mm^(2)/min),demonstrating that electrical discharge assisted helical wire ECM is a promising technique for machining large-thickness hard metal materials.展开更多
Electron-correlated materials have been drawing ever-increasing attention due to their fascinating physical behaviors and extensive application scenarios.In this review,a new method for material research and design(R&...Electron-correlated materials have been drawing ever-increasing attention due to their fascinating physical behaviors and extensive application scenarios.In this review,a new method for material research and design(R&D),named structural-functional unit ordering(SFU ordering),which is presented,overcomes the shortcomings—for example,the limitation of finite chemical elements and long R&D circle-of conventional strategy and thus provides guidance for the design of these high-performance functional materials on demand.Meanwhile,with the development of material characterization technologies,SFUs of different scales and types can be directly observed,which,moreover,regulate the corresponding orderings.The review,starts with an introduction of the profile for SFU ordering and the synergistic effect between SFUs.Then,studies on several new high-performance electronic-correlated materials,for example,a ferromagnetic semiconductor with local spin,ferromagnetic metals with spin topologies,ferroelectric thin films with polar topologies,piezoelectric thin films with nanopillars enclosed by charged boundaries,thermoelectric materials with local ferromagnetic nanoparticles and topotactic phase transformation with conducting nanofilaments are stated in detail one by one.The vital aspect is the breaking of local symmetry,the construction,the structure,of SFUs and their orderings existing or theoretically existing,together with the enhanced/new performance.All in all,the main comments of the review tend to the remaining challenges,promising design approaches for the SFUs,and their orderings for high-performance functional materials.展开更多
In this study,TiN films were deposited on SiO2 substrates by Atomic Layer Deposition(ALD) using TiCl4and NH3 as precursors. Properties and morphology of the TiN films were characterized by different methods.Using Graz...In this study,TiN films were deposited on SiO2 substrates by Atomic Layer Deposition(ALD) using TiCl4and NH3 as precursors. Properties and morphology of the TiN films were characterized by different methods.Using Grazing Incidence X-Ray Diffraction(GIXRD),TiN films demonstrated polycrystalline structure with(111)preferred orientation. Film thickness was measured by Spectroscopic Ellipsometry(SE) and a stable growth rate of 0.0178 nm/cycle was reached after 500 deposition cycles,which was consistent with the essence of ALD as a surface-saturated self-limiting reaction. Film resistivity measured by a four-point probe continuously decreased with increasing deposition cycles until it reached the minimum value of 300μΩ cm at 5000 deposition cycles with a thickness of 87.04 nm. The surface roughness and morphology of the TiN films at different deposition cycles ranging from 50 to 400 were analyzed by Atomic Force Microscopy(AFM). The AFM results indicated that the initial film growth follows the Stranski-Krastanov mode.展开更多
The Yb:Lu_(2)O_(3)precursor made up of spherical particles was synthesized through the co-precipitation method in the water/ethanol solvent.The 5 at% Yb:Lu_(2)O_(3)powder is in the cubic phase after calcination at 110...The Yb:Lu_(2)O_(3)precursor made up of spherical particles was synthesized through the co-precipitation method in the water/ethanol solvent.The 5 at% Yb:Lu_(2)O_(3)powder is in the cubic phase after calcination at 1100℃ for 4 h.The powder also consists of spherical nanoparticles with the average particle and grain sizes of 96 and 49 nm,respectively.The average grain size of the pre-sintered ceramic sample is 526 nm and that of the sample by hot isostatic pressing grows to 612 nm.The 1.0 mm-thick sample has an in-line transmittance of 81.6%(theoretical value of 82.2%)at 1100 nm.The largest absorption cross-section at 976 nm is 0.96×1^(0-20)cm^(2) with the emission cross-section at 1033 nm of 0.92×10^(-20)cm^(2) and the gain cross sections are calculated with the smallest population inversion parameter β of 0.059.The highest slope efficiency of 68.7% with the optical efficiency of 65.1% is obtained at 1033.3 nm in quasi-continuous wave(QCW)pumping.In the case of continuous wave(CW)pumping,the highest slope efficiency is 61.0% with the optical efficiency of 54.1%.The obtained laser performance indicates that Yb:Lu_(2)O_(3)ceramics have excellent resistance to thermal load stresses,which shows great potential in high-power solid-state laser applications.展开更多
Transparent ceramics are at the heart of modern magneto-optical materials providing promising opportunities for Faraday isolators.1.0 at%RE:Tb3Ga5O12(rare earth(RE)=Pr,Tm,Dy)transparent ceramics were successfully prep...Transparent ceramics are at the heart of modern magneto-optical materials providing promising opportunities for Faraday isolators.1.0 at%RE:Tb3Ga5O12(rare earth(RE)=Pr,Tm,Dy)transparent ceramics were successfully prepared by air sintering and sequential HIP technique using the coprecipitated powders as the raw material.All the powders have shown to be a pure cubic terbium gallium garnet(TGG)phase and exhibit good dispersion.Additionally,a change could not be observed in particle shape with the different doped ions.After the two-step sintering,all the obtained ceramics have good optical quality,and the in-line transmittances at 1070 nm are higher than 80%.Moreover,no secondary phase can be detected from the microstructures.However,the pores which remain entrapped in the ceramics can be noted.The Verdet constant of ceramic samples is optimized by RE doping,and the Verdet constant at 632.8 nm is about−143 rad·T^(−1)·m^(−1),which is about 5%higher than that of TGG ceramics.Finally,the thermo-optical properties of 1.0 at%RE:TGG transparent ceramics are compared.The annealed TGG ceramic showed the best thermo-optical properties,and the thermally induced depolarization of 1.0 at%Ce:TGG and 1.0 at%Tm:TGG was inferior to that of annealed TGG ceramic.展开更多
The barrier/seed layer is a key issue in Through Silicon Via(TSV) technology for 3-D integration.Sputtering is an important deposition method for via metallization in semiconductor process. However,due to the limitati...The barrier/seed layer is a key issue in Through Silicon Via(TSV) technology for 3-D integration.Sputtering is an important deposition method for via metallization in semiconductor process. However,due to the limitation of sputtering and a "scallop" profile inside vias,poor step coverage of the barrier/seed layer always occurs in the via metallization process. In this paper,the effects of several sputter parameters(DC power,Ar pressure,deposition time,and substrate temperature) on thin film coverage for TSV applications are investigated.Robust TSVs with aspect ratio 5 1 were obtained with optimized magnetron sputter parameters. In addition,the influences of different sputter parameters are compared and the conclusion could be used as a guideline to select appropriate parameter sets.展开更多
Fine grained 8 mol%yttria-stabilized zirconia(8YSZ)transparent ceramics with high optical and mechanical properties were fabricated by air pre-sintering and hot isostatic pressing(HIP)using commercial 8YSZ powders as ...Fine grained 8 mol%yttria-stabilized zirconia(8YSZ)transparent ceramics with high optical and mechanical properties were fabricated by air pre-sintering and hot isostatic pressing(HIP)using commercial 8YSZ powders as the raw material.The pre-sintered ceramics with fine grains and appropriate relative density play a key role to achieve high transparency and suppressed grain size after HIP post-treatment at relatively low temperatures.With the increase of HIP temperature from 1350 to 1550℃,the in-line transmittance of 8YSZ ceramics at 600 nm increases from 56.9%to 71.5%(2.5 mm in thickness),and the average grain size increases from 2.4 to 16.3μm.The corresponding bending strength of 8YSZ transparent ceramics decreases from 328±20 to 289±19 MPa,the hardness(H)decreases from 12.9±0.1 to 12.5±0.2 GPa,and the fracture toughness(KIC)decreases from 1.30±0.02 to 1.26±0.03 MPa·m^(1/2).Systematical investigations were carried out to study the combination of high optical transparency and excellent mechanical properties in 8YSZ ceramics.展开更多
We proposed a multifunctional terahertz metasurface based on a double L-shaped pattern and a vanadium dioxide(VO_(2)) film separated by polyimide.When the VO_(2)film is an insulator,a dual-band electromagnetically ind...We proposed a multifunctional terahertz metasurface based on a double L-shaped pattern and a vanadium dioxide(VO_(2)) film separated by polyimide.When the VO_(2)film is an insulator,a dual-band electromagnetically induced transparency effect is obtained,and the physical mechanism is investigated based on the current distribution and "two-particle" model.When the VO_(2)film is a metal,a dual-band linear-to-circular polarization converter,in which the y-polarized linear wave can be effectively converted to left-handed circularly polarized(LCP) and right-handed circularly polarized simultaneously in different bands,can be achieved.By arranging the metal pattern rotating 30°,a multifunctional antenna can be obtained.When the VO_(2)is an insulator,the radiation of the LCP wave is divided into four beams,with two beams reflected and two beams transmitted.When the VO_(2)is in the metallic state,we can only get the co-polarized reflected wave with a 21° angle.Moreover,in our design,the VO_(2)film does not need lithography to obtain certain patterns,which improves the convenience of fabrication and experiment.Our design opens a new way for the development of multifunctional terahertz devices and has potential applications in the terahertz communication field.展开更多
基金supported in part by STI 2030-Major Projects under Grant 2022ZD0209200sponsored by Tsinghua-Toyota Joint Research Fund+12 种基金in part by National Natural Science Foundation of China under Grant 62374099, Grant 62022047, Grant U20A20168, Grant 51861145202, Grant 51821003, and Grant 62175219in part by the National Key R&D Program under Grant 2016YFA0200400in part by Beijing Natural Science-Xiaomi Innovation Joint Fund Grant L233009in part supported by Tsinghua University-Zhuhai Huafa Industrial Share Company Joint Institute for Architecture Optoelectronic Technologies (JIAOT KF202204)in part by the Daikin-Tsinghua Union Programin part sponsored by CIE-Tencent Robotics X Rhino-Bird Focused Research Programin part by the Guoqiang Institute, Tsinghua Universityin part by the Research Fund from Beijing Innovation Center for Future Chipin part by Shanxi “1331 Project” Key Subjects Constructionin part by the Youth Innovation Promotion Association of Chinese Academy of Sciences (2019120)the opening fund of Key Laboratory of Science and Technology on Silicon Devices, Chinese Academy of Sciencesin part by the project of MOE Innovation Platformin part by the State Key Laboratory of Integrated Chips and Systems
文摘Due to the constraints imposed by physical effects and performance degra certain limitations in sustaining the advancement of Moore’s law.Two-dimensional(2D)materials have emerged as highly promising candidates for the post-Moore era,offering significant potential in domains such as integrated circuits and next-generation computing.Here,in this review,the progress of 2D semiconductors in process engineering and various electronic applications are summarized.A careful introduction of material synthesis,transistor engineering focused on device configuration,dielectric engineering,contact engineering,and material integration are given first.Then 2D transistors for certain electronic applications including digital and analog circuits,heterogeneous integration chips,and sensing circuits are discussed.Moreover,several promising applications(artificial intelligence chips and quantum chips)based on specific mechanism devices are introduced.Finally,the challenges for 2D materials encountered in achieving circuit-level or system-level applications are analyzed,and potential development pathways or roadmaps are further speculated and outlooked.
文摘Carbonate cements are the most abundant authigenic mineral and impact on physical properties greatly in sandstone reservoir.In this paper,Pinghu Formation of Xihu Sag was taken as a target.Characteristics,distribution and formation of carbonate cements were investigated via optical microscopy,cathodoluminescence(CL),electron probe and in-situ carbon-oxygen isotope.The results showed that carbonate cements varied in types and shapes.Calcite/dolomite mainly present as poikilotopic cements,while ferrocalcite/ferrodolomite/ankerite generally present as pore-filling cements.Carbon isotope(δ^(13)C)values of carbonate cements were ranging from–7.77‰to–2.67‰,with an average of–4.52‰,while oxygen isotope(δ^(18)O)values were ranging from–18.94‰to–12.04‰,with an average of–14.86‰.Theδ^(13)C/δ^(18)O indicated that the paleo-fluid of carbonate cement was mainly freshwater.Organic carbon mainly came from organic matter within mature source rocks,and inorganic carbon came from dissolution of carbonate debris and early carbonate cements.Distinctiveδ^(13)C/δ^(18)O values manifest that carbonate cements with different types formed in different periods,which make different contributions to the reservoir properties.Calcite/dolomite formed during eodiagenesis(70–90℃)and early mesodiagenesis stage(90–120℃),and were favorable to reservoir owing to their compacted resistance and selective dissolution.Ferrocalcite/ferrodolomite/ankerite formed during middle-late mesodiagenetic stage(above 120℃),and were unfavorable to reservoir due to cementing the residual intergranular pores.Hence,in order to evaluate the reservoir characteristics,it is of significantly important to distinguish different types of carbonate cements and explore their origins.
基金the Natural Science Foundation of China(31902166,32030104).
文摘Background Serotonin is an important signaling molecule that regulates secretory and sensory functions in the gut.Gut microbiota has been demonstrated to affect serotonin synthesis in rodent models.However,how gut microbes regulate intestinal serotonin production in piglets remains vague.To investigate the relationship between microbiota and serotonin specifically in the colon,microbial composition and serotonin concentration were analyzed in ileum-cannulated piglets subjected to antibiotic infusion from the ileum when comparing with saline infusion.Microbes that correlated positively with serotonin production were isolated from piglet colon and were further used to investi-gate the regulation mechanisms on serotonin production in IPEC-J2 and a putative enterochromaffin cell line RIN-14B cells.Results Antibiotic infusion increased quantities of Lactobacillus amylovorus(LA)that positively correlated with increased serotonin concentrations in the colon,while no effects observed for Limosilactobacillus reuteri(LR).To understand how microbes regulate serotonin,representative strains of LA,LR,and Streptococcus alactolyticus(SA,enriched in feces from prior observation)were selected for cell culture studies.Compared to the control group,LA,LR and SA supernatants significantly up-regulated tryptophan hydroxylase 1(TPH1)expression and promoted serotonin production in IPEC-J2 cells,while in RIN-14B cells only LA exerted similar action.To investigate potential mechanisms mediated by microbe-derived molecules,microbial metabolites including lactate,acetate,glutamine,andγ-aminobutyric acid were selected for cell treatment based on computational and metabolite profiling in bacte-rial supernatant.Among these metabolites,acetate upregulated the expression of free fatty acid receptor 3 and TPH1 while downregulated indoleamine 2,3-dioxygenase 1.Similar effects were also recapitulated when treating the cells with AR420626,an agonist targeting free fatty acid receptor 3.Conclusions Overall,these results suggest that Lactobacillus amylovorus showed a positive correlation with sero-tonin production in the pig gut and exhibited a remarkable ability to regulate serotonin production in cell cultures.These findings provide evidence that microbial metabolites mediate the dialogue between microbes and host,which reveals a potential approach using microbial manipulation to regulate intestinal serotonin biosynthesis.
基金supported by grants from JSPS/MEXT KAKENHI(JP19H05302 and JP21H00295 to N.W.)the MOST-RIKEN Collaboration Project(2021YFE0108000 to J.L.and N.W.)Translation Research Programs from Fukushima Prefecture(to K.S.).
文摘Myc belongs to a family of proto-oncogenes that encode transcription factors.The overexpression of c-Myc causes many types of cancers.Recently,we established a system for screening c-Myc inhibitors and identified antimycin A by screening the RIKEN NPDepo chemical library.The specific mechanism of promoting tumor cell metastasis by high c-Myc expression remains to be explained.In this study,we screened approximately 5,600 microbial extracts using this system and identified a broth prepared from Streptomyces sp.RK19-A0402 strongly inhibits c-Myc transcriptional activity.After purification of the hit broth,we identified compounds closely related to the aglycone of cytovaricin and had a structure similar to that of oligomycin A.Similar to oligomycin A,the hit compounds inhibited mitochondrial complex V.The mitochondria dysfunction caused by the compounds induced the production of reactive oxygen species(ROS),and the ROS activated GSK3α/βthat phosphorylated c-Myc for ubiquitination.This study provides a successful screening strategy for identifying natural products as potential c-Myc inhibitors as potential anticancer agents.
基金supported by the National Natural Science Foundation of China (21403279, 21507141, 21506243)the Science and Technology Commission of Shanghai Municipality (14DZ1207602, 14DZ1203700)~~
基金supported by the National Science Fund for Distinguished Young Scholars(52025034)National Natural Science Foundation of China(21975204)Innovation Team of Shaanxi Sanqin Scholars。
文摘Combining 3D printing with precursor-derived ceramic for fabricating electromagnetic(EM) wave-absorbing metamaterials has attracted great attention. This study presents a novel ultraviolet-curable polysiloxane precursor for digital light processing(DLP) 3D printing to fabricate ceramic parts with complex geometry, no cracks and linear shrinkage. Guiding with the principles of impedance matching, attenuation, and effective-medium theory, we design a crosshelix-array metamaterial model based on the complex permittivity constant of precursor-derived ceramics. The corresponding ceramic metamaterials can be successfully prepared by DLP printing and subsequent pyrolysis process, achieving a low reflection coefficient and a wide effective absorption bandwidth in the X-band even under high temperature. This is a general method that can be extended to other bands, which can be realized by merely adjusting the unit structure of meta-materials. This strategy provides a novel and effective avenue to achieve “target-design-fabricating” ceramic metamaterials, and it exposes the downstream applications of highly efficient and broad EM wave-absorbing materials and structures with great potential applications.
基金financially supported by the Versus Arthritis (No. 21160)the Rosetree Trust (No. A1184)+2 种基金the European Commission via H2020-MSCA-RISE Program (BAMOS Project (No.734156))Innovate UK via Newton Fund (No. 102872)the Engineering and Physical Science Research Council (EPSRC) via DTP Case Programme (No. EP/T517793/1)
文摘The repair of osteochondral defects is one of the major clinical challenges in orthopaedics.Well-established osteochondral tissue engineering methods have shown promising results for the early treatment of small defects.However,less success has been achieved for the regeneration of large defects,which is mainly due to the mechanical environment of the joint and the heterogeneous nature of the tissue.In this study,we developed a multi-layered osteochondral scaffold to match the heterogeneous nature of osteochondral tissue by harnessing additive manufacturing technologies and combining the established art laser sintering and material extrusion techniques.The developed scaffold is based on a titanium and polylactic acid matrix-reinforced collagen“sandwich”composite system.The microstructure and mechanical properties of the scaffold were examined,and its safety and efficacy in the repair of large osteochondral defects were tested in an ovine condyle model.The 12-week in vivo evaluation period revealed extensive and significantly higher bone in-growth in the multi-layered scaffold compared with the collagen–HAp scaffold,and the achieved stable mechanical fixation provided strong support to the healing of the overlying cartilage,as demonstrated by hyaline-like cartilage formation.The histological examination showed that the regenerated cartilage in the multi-layer scaffold group was superior to that formed in the control group.Chondrogenic genes such as aggrecan and collagen-II were upregulated in the scaffold and were higher than those in the control group.The findings showed the safety and efficacy of the cell-free“translation-ready”osteochondral scaffold,which has the potential to be used in a one-step surgical procedure for the treatment of large osteochondral defects.
基金This study was supported by the National Natural Science Foundation of China(32020103014)Project of Beijing Agricultural Innovation Consortium(BAIC01)The Construction of Beijing Science and Technology Innovation and Service Capacity in Top Subjects(CEFF-PXM2019_014207_000032).
文摘Plant glandular trichomes(GTs)are epidermal outgrowths with the capacity to biosynthesize and secrete specialized metabolites,that are of great scientific and practical significance.Our understanding of the developmental process of GTs is limited,and no single plant species serves as a unique model.Here,we review the genetic mechanisms of GT initiation and development and provide a summary of the biosynthetic pathways of GT-specialized metabolites in nonmodel plant species,especially horticultural crops.We discuss the morphology and classification of GT types.Moreover,we highlight technological advancements in methods employed for investigating GTs.Understanding the molecular basis of GT development and specialized metabolites not only offers useful avenues for research in plant breeding that will lead to the improved production of desirable metabolites,but also provides insights for plant epidermal development research.
基金supported by the National Natural Science Foundation of China(No.11774278)the Fundamental Research Funds for Central Universities(No.2012jdgz04).
文摘Two-dimensional(2D)tungsten selenide(WSe_(2))is promising candidate material for future electronic applications,owing to its potential for ultimate device scaling.For improving the electronic performance of WSe_(2)-based field-effect transistors(FETs),the modification of surface properties is essential.In this study,the seamless structural phase transition in WSe_(2) lattice is achieved by soft oxygen plasma,regulating the electrical conductance of WSe_(2)-based FETs.We found that during the soft oxygen plasma treatment with optimal processing time,the generated oxygen ions can substitute some selenium atoms and thus locally modify the bond length,inducing 2H→1T phase transition in WSe_(2) with seamless interfaces.The mosaic structures have been proven to tailor the electronic structure and increase the hole carrier concentration inside WSe_(2),significantly increasing the channel conductance of WSe_(2) FETs.With the further increase of the oxygen plasma treatment time,the creation of more selenium vacancy defects leads to the electronic doping,resulting in the reduction of conductance.Benefiting from the hexagonal boron nitride(h-BN)encapsulation to interrupt the partial structural relaxation from 1T to 2H phase,our WSe_(2) FET exhibits high electronic stability with conductance of 6.8×10^(-4) S,which is about four orders of magnitude higher than 2H WSe_(2)(5.8×10^(-8) S).This study could further broaden the WSe_(2) FETs in applications for functionalization and integration in electronics.
基金supported by the Guangxi Scholarship Fund of Guangxi Education Department,the Guangxi Med‑ical University Training Program for Distinguished Young Scholars,the Advanced Innovation Teams and Xinghu Scholars Program of Guangxi Medical University,the Guangxi Med‑ical and Health Key Discipline Construction Project,and the Science and Technology Plan Project of Qingxiu District,Nanning(Nos.2020037,2020038,2021007,2021010,and 2021012),China.
文摘Hepatocellular carcinoma(HCC)is one of the most common malignancies and a leading cause of cancer-related death worldwide.Surgery remains the primary and most successful therapy option for the treatment of early-and mid-stage HCCs,but the high heterogeneity of HCC renders prognostic prediction challenging.The construction of relevant prognostic models helps to stratify the prognosis of surgically treated patients and guide personalized clinical decision-making,thereby improving patient survival rates.Currently,the prognostic assessment of HCC is based on several commonly used staging systems,such as Tumor-Node-Metastasis(TNM),Cancer of the Liver Italian Program(CLIP),and Barcelona Clinic Liver Cancer(BCLC).Given the insufficiency of these staging systems and the aim to improve the accuracy of prognostic prediction,researchers have incorporated further prognostic factors,such as microvascular infiltration,and proposed some new prognostic models for HCC.To provide insights into the prospects of clinical oncology research,this review describes the commonly used HCC staging systems and new models proposed in recent years.
基金the financial support provided by the National Natural Science Foundation of China(No.52175413)the Natural Science Foundation of Jiangsu Province(No.BK20192007)+3 种基金the National Natural Science Foundation of China for Creative Research Groups(No.51921003)the Fundamental Research Funds for the Central Universities(No.NS2021034)the Aeronautical Science Foundation of China(No.201907052002)the Interdisciplinary Innovation Fund for Doctoral Students of Nanjing University of Aeronautics and Astronautics(No.KXKCXJJ202207).
文摘Wire electrochemical machining(WECM) is a flexible and effective method for machining complex-shaped metal components, but the ability to machine large-thickness workpieces is hampered by the difficulty of transporting electrolytic products in the narrow machining gap. This paper proposes a novel hybrid machining technique that combines the characteristics of WECM and wire electric discharge machining(WEDM), namely, helical wire electrochemical discharge machining. The formation mechanism of electrical discharge in salt-glycol solution was elucidated.Experiments and simulation were conducted to verify the machining mechanism and investigate the performance of the proposed technique. The results show that as the recast layer can be removed by electrochemical action during the proposed process, the surface quality is effectively improved.Minimum surface roughness of the slit sidewall after machining reaches Ra= 0.12 μm. Minimum standard deviation of the slit after machining reaches 5 μm. Moreover, the existence of the discharges significantly improves the transport of the electrolytic products, thus ensuring high machining efficiency. In the experiments, the maximum feed rate of the helical wire electrochemical discharge machining reaches 7 μm/s(12.6 mm^(2)/min). Finally, mortise structures of Inconel 718 with good machining accuracy and surface quality are fabricated with a feed rate of 5 μm/s(9 mm^(2)/min),demonstrating that electrical discharge assisted helical wire ECM is a promising technique for machining large-thickness hard metal materials.
基金the financial support from the National Key R&D Program of China(2021YFB3201100)the National Natural Science Foundation of China(52172128)the Top Young Talents Programme of Xi'an Jiaotong University.
文摘Electron-correlated materials have been drawing ever-increasing attention due to their fascinating physical behaviors and extensive application scenarios.In this review,a new method for material research and design(R&D),named structural-functional unit ordering(SFU ordering),which is presented,overcomes the shortcomings—for example,the limitation of finite chemical elements and long R&D circle-of conventional strategy and thus provides guidance for the design of these high-performance functional materials on demand.Meanwhile,with the development of material characterization technologies,SFUs of different scales and types can be directly observed,which,moreover,regulate the corresponding orderings.The review,starts with an introduction of the profile for SFU ordering and the synergistic effect between SFUs.Then,studies on several new high-performance electronic-correlated materials,for example,a ferromagnetic semiconductor with local spin,ferromagnetic metals with spin topologies,ferroelectric thin films with polar topologies,piezoelectric thin films with nanopillars enclosed by charged boundaries,thermoelectric materials with local ferromagnetic nanoparticles and topotactic phase transformation with conducting nanofilaments are stated in detail one by one.The vital aspect is the breaking of local symmetry,the construction,the structure,of SFUs and their orderings existing or theoretically existing,together with the enhanced/new performance.All in all,the main comments of the review tend to the remaining challenges,promising design approaches for the SFUs,and their orderings for high-performance functional materials.
基金supported by the National Natural Science Foundation of China (No. 61274111)
文摘In this study,TiN films were deposited on SiO2 substrates by Atomic Layer Deposition(ALD) using TiCl4and NH3 as precursors. Properties and morphology of the TiN films were characterized by different methods.Using Grazing Incidence X-Ray Diffraction(GIXRD),TiN films demonstrated polycrystalline structure with(111)preferred orientation. Film thickness was measured by Spectroscopic Ellipsometry(SE) and a stable growth rate of 0.0178 nm/cycle was reached after 500 deposition cycles,which was consistent with the essence of ALD as a surface-saturated self-limiting reaction. Film resistivity measured by a four-point probe continuously decreased with increasing deposition cycles until it reached the minimum value of 300μΩ cm at 5000 deposition cycles with a thickness of 87.04 nm. The surface roughness and morphology of the TiN films at different deposition cycles ranging from 50 to 400 were analyzed by Atomic Force Microscopy(AFM). The AFM results indicated that the initial film growth follows the Stranski-Krastanov mode.
基金supported by the National Key R&D Program of China(Grant No.2017YFB0310500)the National Natural Science Foundation of China(Grant No.61575212)the Key Research Project of the Frontier Science of the Chinese Academy of Sciences(No.QYZDB-SSW-JSC022).
文摘The Yb:Lu_(2)O_(3)precursor made up of spherical particles was synthesized through the co-precipitation method in the water/ethanol solvent.The 5 at% Yb:Lu_(2)O_(3)powder is in the cubic phase after calcination at 1100℃ for 4 h.The powder also consists of spherical nanoparticles with the average particle and grain sizes of 96 and 49 nm,respectively.The average grain size of the pre-sintered ceramic sample is 526 nm and that of the sample by hot isostatic pressing grows to 612 nm.The 1.0 mm-thick sample has an in-line transmittance of 81.6%(theoretical value of 82.2%)at 1100 nm.The largest absorption cross-section at 976 nm is 0.96×1^(0-20)cm^(2) with the emission cross-section at 1033 nm of 0.92×10^(-20)cm^(2) and the gain cross sections are calculated with the smallest population inversion parameter β of 0.059.The highest slope efficiency of 68.7% with the optical efficiency of 65.1% is obtained at 1033.3 nm in quasi-continuous wave(QCW)pumping.In the case of continuous wave(CW)pumping,the highest slope efficiency is 61.0% with the optical efficiency of 54.1%.The obtained laser performance indicates that Yb:Lu_(2)O_(3)ceramics have excellent resistance to thermal load stresses,which shows great potential in high-power solid-state laser applications.
基金supported by the National Key R&D Program of China(Grant No.2017YFB0310500)the NSFC-RFBR Cooperative Research Project(Grant No.61911530135)+1 种基金the Key Research Project of the Frontier Science of the Chinese Academy of Sciences(No.QYZDB-SSW-JSC022)supported partially by the Ministry of High Education and Science of the Russian Federation and the State Task executed in the Institute of Applied Physics RAS(Project No.00352019-0015)。
文摘Transparent ceramics are at the heart of modern magneto-optical materials providing promising opportunities for Faraday isolators.1.0 at%RE:Tb3Ga5O12(rare earth(RE)=Pr,Tm,Dy)transparent ceramics were successfully prepared by air sintering and sequential HIP technique using the coprecipitated powders as the raw material.All the powders have shown to be a pure cubic terbium gallium garnet(TGG)phase and exhibit good dispersion.Additionally,a change could not be observed in particle shape with the different doped ions.After the two-step sintering,all the obtained ceramics have good optical quality,and the in-line transmittances at 1070 nm are higher than 80%.Moreover,no secondary phase can be detected from the microstructures.However,the pores which remain entrapped in the ceramics can be noted.The Verdet constant of ceramic samples is optimized by RE doping,and the Verdet constant at 632.8 nm is about−143 rad·T^(−1)·m^(−1),which is about 5%higher than that of TGG ceramics.Finally,the thermo-optical properties of 1.0 at%RE:TGG transparent ceramics are compared.The annealed TGG ceramic showed the best thermo-optical properties,and the thermally induced depolarization of 1.0 at%Ce:TGG and 1.0 at%Tm:TGG was inferior to that of annealed TGG ceramic.
基金supported by the National Natural Science Foundation of China (No. 61274111)he National Science & Technology Major Project of China (No. 2011ZX02709)
文摘The barrier/seed layer is a key issue in Through Silicon Via(TSV) technology for 3-D integration.Sputtering is an important deposition method for via metallization in semiconductor process. However,due to the limitation of sputtering and a "scallop" profile inside vias,poor step coverage of the barrier/seed layer always occurs in the via metallization process. In this paper,the effects of several sputter parameters(DC power,Ar pressure,deposition time,and substrate temperature) on thin film coverage for TSV applications are investigated.Robust TSVs with aspect ratio 5 1 were obtained with optimized magnetron sputter parameters. In addition,the influences of different sputter parameters are compared and the conclusion could be used as a guideline to select appropriate parameter sets.
基金This work was supported by the National Key R&D Program of China(Grant No.2021YFE0104800)the Key Research Project of Frontier Science of Chinese Academy of Sciences(Grant No.QYZDB-SSW-JSC022).
文摘Fine grained 8 mol%yttria-stabilized zirconia(8YSZ)transparent ceramics with high optical and mechanical properties were fabricated by air pre-sintering and hot isostatic pressing(HIP)using commercial 8YSZ powders as the raw material.The pre-sintered ceramics with fine grains and appropriate relative density play a key role to achieve high transparency and suppressed grain size after HIP post-treatment at relatively low temperatures.With the increase of HIP temperature from 1350 to 1550℃,the in-line transmittance of 8YSZ ceramics at 600 nm increases from 56.9%to 71.5%(2.5 mm in thickness),and the average grain size increases from 2.4 to 16.3μm.The corresponding bending strength of 8YSZ transparent ceramics decreases from 328±20 to 289±19 MPa,the hardness(H)decreases from 12.9±0.1 to 12.5±0.2 GPa,and the fracture toughness(KIC)decreases from 1.30±0.02 to 1.26±0.03 MPa·m^(1/2).Systematical investigations were carried out to study the combination of high optical transparency and excellent mechanical properties in 8YSZ ceramics.
基金supported by the National Natural Science Foundation of China (Nos. 62175016, 61875017, and 61871419)Fundamental Research Funds for the Central Universities (No. 2020RC02)+1 种基金Shenzhen Science and Technology Plan Basic Research Project (No. JCYJ20180305164708625)BUPT Excellent PhD Students Foundation (No. CX2020110)
文摘We proposed a multifunctional terahertz metasurface based on a double L-shaped pattern and a vanadium dioxide(VO_(2)) film separated by polyimide.When the VO_(2)film is an insulator,a dual-band electromagnetically induced transparency effect is obtained,and the physical mechanism is investigated based on the current distribution and "two-particle" model.When the VO_(2)film is a metal,a dual-band linear-to-circular polarization converter,in which the y-polarized linear wave can be effectively converted to left-handed circularly polarized(LCP) and right-handed circularly polarized simultaneously in different bands,can be achieved.By arranging the metal pattern rotating 30°,a multifunctional antenna can be obtained.When the VO_(2)is an insulator,the radiation of the LCP wave is divided into four beams,with two beams reflected and two beams transmitted.When the VO_(2)is in the metallic state,we can only get the co-polarized reflected wave with a 21° angle.Moreover,in our design,the VO_(2)film does not need lithography to obtain certain patterns,which improves the convenience of fabrication and experiment.Our design opens a new way for the development of multifunctional terahertz devices and has potential applications in the terahertz communication field.
